The fields of machine system salvaging and remanufacturing have grown rapidly in recent years. Systems and components that only recently would have been considered scrap are now rebuilt, refurbished, etc., and returned to service. A wide variety of repair-related technologies has accompanied expansion of these fields. In the past, it was common for a “rebuilt” machine system such as an engine to be returned to service only after its dimensions, operating characteristics, etc. had been modified from original specs. It is now increasingly common for systems and components to be remanufactured to a condition as good as new. The development of repair and remanufacturing strategies in certain technical areas has been rapid. In other areas, however, and in the case of certain specific parts, engineers have found it more challenging to return components to a commercially and technically acceptable state, much less a condition identical to that held in a former service life.
The repair and rebuilding of certain parts commonly used in locomotives is one area where improved repair strategies would be welcomed. One component of interest is known in the art as a bearing taper roller or “BTR” housing. BTR housings are used in locomotive systems to support traction motors for applying driving torque to axles/wheels of the locomotive. A set of bearings are typically positioned between a locomotive axle and the BTR housing to rotatably journal the axle therein. Application of driving force from electric motors on the axle, typically via a gearbox, tends to eventually result in problematic wear to portions of the BTR housing. This wear is apparently due at least in part to separating forces between drive gears in the propulsion system. When certain locomotive subassemblies are disassembled for remanufacturing, it is typically desirable to repair the wear on one or more BTR housings if they are otherwise suited to returning to service. Wear problems have been shown to be especially acute in regions of BTR housings supporting the bearings that journal the locomotive axle.
The bearings used to rotatably journal axles within BTR housings typically consist of taper ring bearing assemblies pressed or shrink fitted into bores at opposite ends of the BTR housing. Over the course of many hours of operation, the aforementioned forces have a tendency to create worn regions within the bearing bores. This type of wear often develops asymmetrically within the bearing bores due to the asymmetric nature of the forces responsible therefor. A consequence of overly worn bearing bores can be uneven stress and strain on components, and potentially premature fatigue or failure.
To address these issues, technicians have previously placed sleeves and the like into the bearing bores to support replacement bearings therein. It is typically quite difficult or impossible to remanufacture the BTR housing a second time, however, where this strategy is used. Reversing the connections between the parts is difficult. Furthermore, one or both of the process of engaging the sleeve in the bearing bore, and removing it, can deform or otherwise alter the housing and/or bearing bores such that they are poorly suited to receiving and supporting such sleeves in a second round of remanufacturing. Other attempts at repairing bearing bores in BTR housings have included the application of resurfacing material. These techniques have not met with success due to the tendency for residual grease within the bore to interfere with adhesion of resurfacing material.